Motor controller



Mo'ron CONTROLLER Filed Jan. 24, 1924 2 Sheets-Sheet 1 WITNESS:

Y 1,625,773 Aprl 19 1927' 'w. B. PARK MOTOR CONTROLLER File@ Jan. 24. 1924 2 Sheets-Sheet 2 O O O O O C O O O l f Cz( i' i ffy-@"- ATTORNEY WITNESS:

Patented Apr. 19, 1927.

UNITED STATES PATENT OFFICE.

WILLIAM IB. PARK, 0F LINTON, INDIANA, ASSIGNOR OF'ONE-HALF T0 CIYDIE M. ZINK, 0F LINTON, INDIANA.

MOTOR CON TROLLER'.

Application led January 24, 1924. Serial- No. 688,312.

This invention relates to electrical control devices,c particularly to controllers for electric haulage motors and the like, and has for itsobject the provision of a novel finger bar and terminal arrangement possessing marked advantages over the usual construction'.

It is well known that controller boxes of this general character embody two rotary cylinders having contact segments co-operating with contact fingers connected with the respective power supply lines and motor leads, one cylinder acting to regulate the speed of the motor and the other controlling the reverse. In the ordinary construction, the fingers are carried by a wooden bar to which they are rigidly bolted and have their terminals so mounted that the current must pass through the fingers themselves to the various motor leads. This construction is faulty in several respects. The `principal object is that the current passing through the spring fingers causes excessive heating thereof, which in a comparatively short time, reduces and eventually destroys the temper so that the fingers lose their resilience and fail to make close contact with the segments.` This condition causesarcing at the points of contact which naturally soon results in burning away the fingers yand rendering them useless. Another disadvantage is that the finger bar, being Wooden, does not possess the proper strength and durability so that eventually thebolts holding the fingers become kloose and permit the fingers to move, thereby causing poor contact. The first mentioned objection is a seriousv one inasmuch as burning and detempering of the fingers necessitates entire replacement. The ordinary arrangement or construction is defective in other respects as isvknown to those skilled in the art.

. It' is with the above conditions in view that I have designed the present invention which contemplates the construction of the finger bar from or as a metal frame upon which the various fingers are detachably mounted and insulated, the frame being formed for the accommodation of the usual areV guards located between the successive fingers.-

The essential feature is the location or disposition of the terminals upony the ends of rangement preventing heating and detemy pering of the fingers.

Another object is the provision of a finger emistruction inwhich the contact shoes or burning points` are detachably mounted upon the free ends of the fingers so as to be capable of replacement when worn or burned, itbeing unnecessary to discard the entire finger itself, the shoes beingmoreover, held by screws passing downwardly through the finger. y

Other obfects and advantages such as simplicity in construction, ease of manufacture, accessibility for repairs and replacements, durability, economy and the general improvement ofI the art will become apparent during the course of the following description in conjunction with the drawings, in which* Figure l is a view of a controller boX embodying my invention, the cover of the boX being removedV and the arc guards being shown in section, the plane of the View beying indicated by the line 1*-1 in Figure 2,

Figure 2 is a section on the line 2-2 of Figure l.

Figure 3 is a bottom finger bar.

Figure i is a side elevation thereof. Figure 5 isa diagram of the electric circuit.

Referring more particularly to the drawings the letter A represents a controller boX within which are rotatably mounted the controller cylinders B and C operable in the usual manner andv carrying the usual segments D and E respectively. The cylinder B controls the motor speed while the cylinder C controls the direction. The letter F represents a resistance tapped at several points and having its leads connected with contacts IQL, P and with a blow out coil G which is, in turn, connected with a pair of contacts U., One feed wire H connects with a contact V,while the other I connects with one terminal yof the series field J of the motor. One terminal` of the shunt field coils W is connected with the contact K. lThe contacts X and Z arey connected with the plan View of the ico motor brushes. rEhe remaining terminal of the series field is connected with a contact Y. The two ields are connected as shown at S. The contacts K, U, l), L and V cooperate with the segments D while the contacts X, il, Z and Y cooperate with the contact segments E. rlhis wiring or mode ot connection is conventional and no claim is made thereto, the matter being described and illustrated solely for the sake ot clearness. For this reason a tracing out o'l the circuits is unnecessary as the action will be easily understood by one skilled in the art.

ln carrying out the invention I provide a linger bar designated broadly by the numeral 10 and formed as an angular trame oic metal,` preferably iron having attaching feet 11 by means ot which it may be properly mounted in the box A. This trame embodies a bar 12 having secured thereon an insulating coverinff 18 ot' any suitable ma- `lerial but preferably ot mica. The edges of this covering extend downwardly as shown at le to cover the edges ot the bar. Atone edge the bar and insulating coveringare notched or cut away as indicated at 15 tor the accommodation ot the are guards 1G which are ot ordinary construction. The lrame further includes a partition bar or plate 1( spaced somewhat from the bar 12 and extending beneath the notches 15 to 'torni a restl tor the arc guards as clearly disclosed in Figure 2.

'l`he tingers corresponding to the contact l, ll, l), L, V, X, U, Z and Y are all carried by the trame 10. Each linger comprises a resilient or spring strip iSdisposed upon the insulating covering 13 and secured by suitable screws 19 which pass through an insulating block er strip 2O disposed upon the linger and which also pass through suitable insulating bushings 21 extending through holes in the nger and abutting against the covering 13. By this mounting it is evident that the lingers will be securely held upon the linger bar and at the same time clleetually insulated therelrom and consequently from one another.

Carried by the tree end ol' each linger 1s a relatively large and heavy contact shoe 22 having a curved tace tor coaetion with the associated cylinder segment. also carried by the :tree end of each linger, is a. terminal connection comprising a socket member 23 and a plate like base 2li. rlhe terminal and shoe are both held upon the linger and in fixed relation to each other by suitable screws or the like 95 which pa through the base plate Q4, through the linger and into the shoe. The sockets Q3 are -tor the reception of the ends ot the cables which are held therein by suitable set screws 26.

Two socket members Q7 and 28 a e here represented as being double or having two holes therein tor connection ot two cables therewith, these socket members being carried by the lingers which correspond to the contacts U so that the necessary blow out coil connection may be made thereto. However there is no limitation whatever as to whether or not one or more sockets or terminals are made double or single. y

ln the use ot' the device it is obvious that the current passes directly through the contact shoes and terminal members Without passing throughout the length of the lingers. ln this way it will be apparentthat heating, or at. least excessive heating ot' the ngers and consequent detempering will be 4prevented. The great advantage of this feature is that the linges will retain their proper resilience for an indefinite period and will not need to be replaced as is the case iny the ordinary construction and arrangement. 'lhe act-ion ot my invention is the same as the action oit the ordinary arrangement in so tar as the controlling of the motor is concerned. lt will be noted that the contact shoes are relatively heavy so as to be capable of prolonged use before becoming worn or burnt to such an extent as to necessitate replacement. l'lvlhenever it should occur that a contact shoe requires replacement, such may be accomplished without disturbing the mounting of the linger itselr', the screws 25 being removed to etlect removal ot the shoe, a new shoe being placed in position and the screws replaced. lt by chance it does become desirable to replace an entire linger, it is obvious that this may likewise be accomplished in an ext-remely simple manner by removing the screws i9 and4 placing the new ringer in position without disturbing the mounting ot' the bar or any other parts ot the mechanism.

Summing up it will be apparent that I have thus provided a very simple, easy and cheaply built linger bar and linger construction wherein maximum durability, efficiency, economy and accessibility will be assured with the minimum likelihood of derangement and expenditure of time and labor for making adjustments, repairs or replacements.

Vlhile I have shown and described the invention as involving a certain number of lingers and while the diagram represents the device as used lin connection with direct current motors, it is obvious that the number of lingers may be increased or decreased depending upon the specific controller system and it is likewise evident that the arrangement may be varied :tor use in connection with alternating current motors. I reserve the right to make all these changes, modilicat-ion or variations together with all others in the details ot construction and arrangement provided there is no departure from the spirit or' the invention or the scope ot the subjoined claim.

I claim:

In a motor controller, a casing, drums mounted therein und carryin contacte, a finger bar formed as ny metal frame located 5 between the drums, fingers mounted upon and insulated from the finger har und cooperating With the respective drums, an

elongated support carried by the finger bar, the edge of the finger bar toward one drum being notched, and a plurality of arc guards 10 located Within said notches and resting upon said support.

In testimony whereof I affix my signature.

WILLIAM B. PARK. 

